Otolith

“ An excretory system has not hitherto been seen. Yolk-glands are absent. An otolith underlies the brain. The Acoela are marine.
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(2) Rhabdocoela, which possess a complete alimentary tract separated from the body-wall (except for a few suspensory strands) by a space or body-cavity, filled with fluid. This space is sometimes (Vortex viridis) lined by an endothelium of flattened parenchymatous cells. There are two compact testes, which are enclosed (as are the ovaries and yolk-glands) in a distinct membrane. An otolith is present in some genera and species. Terrestrial, fresh-water, marine. ”

“ What we call the auditive organ is in the lower animals simply a sac containing auditive stones. As we ascend the scale, 1, 2, 3 semi-circular canals gradually develop from them, whilst the structure of the otolith organ itself becomes more complicated. Finally, in the higher vertebrates, and particularly in the mammals, a part of the latter organ (the lagena) becomes the cochlea, which Helmholtz explained as the organ for sensations of tone. ”

“ In a very few turbellaria we find otolith vesicles. [50] These are little sacks in the skin, lined with neuro-epithelial cells and having in the middle a little concretion of carbonate of lime hung on rather a stiffer hair, like a clapper in a bell. Such organs serve in higher animals as organs of hearing, for the sensory hairs are set in vibration by the sound-waves. It is quite as probable that they here serve as organs for feeling the slightest vibrations in the surrounding water, and thus giving warning of approaching food or danger. ”

“ Animals furnished with otoliths can thus analyze rhythms and disturbances which are synthetized in our cochlea into sounds of different tones. The otolithic bell can only reveal a trepidation, and continues unfit to provoke a continuous sensation other than that which results from the persistance of nervous, terminal, or central impressions, a limit beyond which it can not estimate the pitch without such an arrangement as that of the cochlear formations. ”

“ In the "vestibule", the central part of the inner ear, the hair-tips of the sense cells are matted together, and in the mat are imbedded little particles of stony matter, called the "otoliths". When the head is inclined in any direction, these heavy particles sag and bend the hairs, so stimulating them ”

“ In the case of the open sacks the otoliths appear to be simply stones transported into the interior of the sacks, but in the closed sacks the otoliths, though free, are no doubt developed within the sacks. ”

“ A strange case is reported in a girl of fourteen, who lost her tympanum from a profuse otorrhea, and who substituted an artificial tympanum which was, in its turn, lost by deep penetration, causing augmentation of the symptoms, of the cause of which the patient herself seemed unaware. Sometimes artificial otoliths are produced by the insufflation of various powders which become agglutinated, and are veritable foreign bodies. Holman tells of a negro, aged thirty-five, whose wife poured molten pewter in his ear while asleep. It was removed, but total deafness was the result. ”

“ The structure of one is exhibited in fig. 20. A single otolith is present as in the veliger embryos of Opisthobranchia. In Filibranchia and many Protobranchia the otocyst (or statocyst) contains numerous particles (otoconia) . The organs are developed as invaginations of the epidermis of the foot, and in the majority of the Protobranchia the orifice of invagination remains open throughout life; this is also the case in Mytilus including the common mussel.
Anodonta has no eyes of any sort, and the tentacles on the mantle edge are limited to its posterior border. ”

“ At the fundus are placed the concrement-cells with their conspicuous otoliths (con) and the inconspicuous auditory cells, which are connected with. the sub-umbral nerve-ring. From the open condition arises the closed condition very simply by closing up of the aperture of the pit. We then find the typical otocyst of the Leptomedusae, a vesicle bulging on the ex-umbral side of the velum (figs. 32, 33) . The otocysts are placed on the outer wall of the vesicle (the fundus of the original pit) or on its sides ”

“ By means of cilia, which connect with sense-cells, these otoliths are given a peculiar movement or oscillation in the medium in which they are suspended. The number of the otoliths varies in different genera and species; there are several hundreds in Arion and Limax, about a hundred in Helix pomatia, nemoralis, hispida, arbustorum, rotundata, Succinea putris, and Limnaea stagnalis; about fifty in Planorbis contortus and Physa fontinalis, only one in Cyclostoma elegans. The number increases with age. In young specimens of Limn. stagnalis as few as ten, nine, and seven have been noticed. ”

“ I only say that all animals possessing the otolithic apparatus in any of its forms perceive, of disturbances of the medium, the intensity, the direction, and the number only, but can not convert them into continuous sensations like those we call sounds. ”

“ In animals it has been observed that orientation toward the center of gravity of the earth often becomes less compulsory when the inner ear has been removed. Mach first pointed out the possibility that the otoliths are responsible for this. They might press upon the end-organs of the sensory nerves and every change of pressure might cause a correction of the position of the animal. It is generally assumed that this view has been verified by experiment. ”

“ In human ears the limits of hearing are reached when about 35,000 vibrations strike the drum of the ear in a second.
Whatever the explanation of the gift of hearing in ourselves may be, different plans seem to be adopted in the case of other animals. In many Crustacea and Insects there are flattened hairs each connected with a nerve fibre, and so constituted as to vibrate in response to particular notes. In others the ear cavity contains certain minute solid bodies, known as otoliths, which in the same way play upon the nerve fibres. ”

“ Experiment 157. To vibrate the tympanic membrane and the little ear-bones. Shut the mouth, and pinch the nose tightly. Try to force air through the nose. The air dilates the Eustachian tube, and is forced into the ear-drum. The distinct crackle, or clicking sound, is due to the movement of the ear-bones and the tympanic membrane.
The cochlea, or snail’s shell, is another chamber hollowed out in the solid bone. It is coiled on itself somewhat like a snail’s shell. There is a central pillar, around which winds a long spiral canal. One passage from the cochlea opens directly into the vestibule ”

“ No one except myself saw that Ottilie was disturbed. She has a way when she experiences any sharp unpleasant emotion which she wishes to resist, of showing it in the unequal color of her face; the left cheek becomes for a moment flushed, while the right turns pale. I perceived this symptom, and I could not prevent myself from saying something. I took our Superior aside, and spoke seriously to her about it. ”

“ For three days and nights, spell and spell, on the cover and in the water, we drifted over the ocean. Toward the last I was delirious most of the time, and there were times, too, when I heard Otoo babbling and raving in his native tongue. Our continuous immersion prevented us from dying of thirst, though the sea water and the sunshine gave us the prettiest imaginable combination of salt pickle and sunburn. In the end, Otoo saved my life; for I came to, lying on the beach twenty feet from the water, sheltered from the sun by a couple of cocoanut leaves. ”

“ Odontalgia may be distinguished from otitis by the application of cold water to the affected tooth; for as the pain of common tooth-ach is owing to torpor, whatever decreases stimulus adds to the torpor and consequent pain; whereas the pain of an inflamed tooth being ceased by the increased action of the membranes of it is in some measure alleviated by the application of cold.
8. Otitis. Inflammation and consequent suppuration of some membranes of the internal ear frequently occur in children, who sleep in cold rooms, or near a cold wall, without a night-cap. ”

“ Here is a pigmentary spot to which we assign the dignity of the eye; there, a hair, an otocyst, which we call the auditory organ; and at the same time we assume that the spot is for seeing and the hair for hearing. As sight and hearing are known to us only as we have them, there results a deplorable misinterpretation of the sensorial function in animals. ”

“ THE OSTLER.
I find an old man, fast asleep, in one of the stalls of the stable. It is midday, and rather a strange time for an ostler to devote to sleep. Something curious, too, about the man's face. A withered, woe-begone face. The eyebrows painfully contracted; the mouth fast set, and drawn down at the corners; the hollow cheeks sadly, and, as I cannot help fancying, prematurely wrinkled; the scanty, grizzled hair, telling weakly its own tale of some past sorrow or suffering. How fast he draws his. breath, too, for a man asleep! ”

“ The human ear would seem to present greater difficulties. For the essential part of the sense-organ, in this case, is the membranous labyrinth, a bag of complicated form, which lies buried in the depths of the floor of the skull, and is surrounded by dense and solid bone. Here, however, recourse to the study of development readily unravels the mystery. Shortly after the time when the olfactory organ appears as a depression of the skin on the side of the fore-part of the head, the auditory organ appears as a similar depression on the side of its back part. ”

“ In the ear, the receptive organ for the astral impulses pressing in upon it is a part which belongs to the body's limb system, while it is the nervous organization which functions as the organ of response. For in the ear the sound-waves are first of all taken over by the so-called ossicles, three small bones in the middle ear which, when examined with the Goethean eye, appear to be a complete metamorphosis of ah arm or a leg. ”

“ He concluded that the otocysts must possess, besides their auditory functions, a power which stands in some relation to the proper orientation of the body in locomotion, a power which is not wholly supplied by sight and touch alone. The otocysts may thus regulate locomotion by stimulating muscular acts which tend to keep the body in the straight line during the process of movement. ”

“ In the young skull of Euotaria nigrescens the hinder end of the tooth-line is very near (not a quarter of an inch from) a line level with the front edge of the internal nasal opening, and the hinder part of the palate in front of the aperture is nearly as broad as the middle of the palate: in the adult skull the hinder end of the tooth-line is a full inch from the front edge of the internal nasal opening, the hinder part of the palate is contracted toward the internal nostril, and the internal nasal opening is lengthened and narrowed ”

“ She had eyes everywhere—not only in the back of her head, as the ostler and the maid at the Seven Thorns said, but at the tips of her fingers, and in the handle of the broom with which she was as usual sweeping briskly out the dust and sand of yesterday, and striking into every corner. ”

“ She bends over HYGD and kisses her; they laugh softly together. LEAR parts the curtains of the door at the back, stands there a moment, then goes away noiselessly.
The lish baby otter
Is sleeky and streaming,
With catching bright fishes
Ere babies learn dreaming;
But no wet little otter
Is ever so warm
As the fleecy-wrapt baby
'Twixt me and my arm.
Sleep big mousie...
Hygd (suddenly irritable) :
Be quiet ... ”

“ This new sound came upwards from the ground—a low, moaning, wailing voice, full of suffering and pain. The contrast between it and the hoot of the owl was indescribable; the one with a wholesome wildness and naturalness that hurt nobody—the other, a sound that made one's blood curdle, full of human misery. With a great deal of fumbling—for in spite of everything I could do to keep up my courage my hands shook—I managed to remove the slide of my lantern. The light leaped out like something living, and made the place visible in a moment. ”

“ The organ of hearing is without any external ear and without an air-containing external auditory meatus. The aerial vibrations do not pass, as in other mammals, from the external auditory passage to the tympanic cavity and thus to the nerve-terminations of the inner ear; but they reach the tympanic cavity by direct transmission through the bones of the skull, which possess a special structure and contain abundant air-cavities. ”

“ Then the morass and all the hills about it were bathed in the glow, and the swollen stream, visible over the edge of the nest, glistened like silver. Quick to accept Nature’s bounty for the winterlings, the otter, when satisfied that no eye observed her, took them between her lips, carried them from the gloomy hover, and laid them on a tussock which screened her where she crouched, ready to protect them. There the cubs stretched themselves and basked with quiet content in the health-giving rays. ”

“ For some years this specialty throve on the otitis acquired at the bathing-houses at Rockaway and Coney Island, but the public discovered that a little cotton in the meatus was the needful prophylactic, and otitis, as a source of revenue, dwindled to the starvation point. Again, and for a time, the horn of plenty overflows in the otologist’s operating room, and his commissions to the car conductors promise to put them soon on a plane with the diamond-bedecked shirt-fronts of the average hotel clerk. ”

“ Though the wild promontory is steeped in legend and romance, though tales of giants, fairies, smugglers and shipwrecked sailors, abound, there is no story the crofters so often repeat by the firelight as the story of the otter, none the children listen to with closer attention. Mary's three boys never wearied of hearing their mother tell how she stood on the rick and watched the hounds stream through the Fairies' Gap ”